Retatrutide (Reta) vs Semaglutide (the Ozempic Molecule)
Weight Loss & Metabolism Research
Semaglutide works on one receptor. Retatrutide works on three. That is the entire technical difference behind “reta vs sema” — but the two also sit in completely different legal categories, and mixing that up is the most common confusion in this space.
Two different categories, not just two molecules
Semaglutide is a GLP-1 receptor agonist and the active molecule in Ozempic and Wegovy — approved human medicines, prescribed by physicians and dispensed by pharmacies.
Retatrutide (“reta”) is a GLP-1 + GIP + glucagon triple receptor agonist still in clinical development. It is not approved anywhere, has no brand-name product, and exists outside trials only as a laboratory research material.
So “retatrutide vs Ozempic” is not really a product comparison. One is a medicine you get from a doctor; the other is a research compound you get from a research supplier.
The receptor arithmetic
- Semaglutide — GLP-1 only. The single-receptor baseline of the incretin class, with the deepest published literature.
- Tirzepatide — GLP-1 + GIP. The dual agonist, sitting between the other two. We compared it with reta directly in Retatrutide vs Tirzepatide.
- Retatrutide — GLP-1 + GIP + glucagon. The triple agonist and the newest of the three; the glucagon receptor is what no other compound in the class engages.
Receptor count is not a potency ranking — it is a difference in what research questions each molecule can answer. Single-, dual- and triple-agonist compounds are different tools, which is why comparative laboratories work with more than one.
What a research supplier can and cannot offer
Vistara Labs supplies retatrutide (reta) in 10 mg and 20 mg vials and tirzepatide in 10 mg vials — both lyophilised, third-party tested, COAs on request, shipped from within Canada. We do not sell semaglutide, and no research vendor sells Ozempic: brand-name incretin medicines belong to the pharmacy system.
Frequently asked questions
Is retatrutide the same as Ozempic?
No. Ozempic is a brand-name medicine containing semaglutide, a single-receptor GLP-1 agonist. Retatrutide is a different, unapproved molecule that engages three receptors and exists only as a research material.
Is retatrutide a GLP-1?
It is a GLP-1 receptor agonist, among other things — it also engages the GIP and glucagon receptors, which is why it is called a triple agonist rather than a GLP-1.
Where can I get reta in Canada?
From a Canadian research supplier. Vistara Labs ships retatrutide from within Canada with COAs available on request, for laboratory research use only. See our full note on where to get retatrutide in Canada.
All products supplied by Vistara Labs are intended for laboratory research use only. They are not drugs, are not approved for human or veterinary use, and are not intended to diagnose, treat, cure or prevent any condition. Nothing on this page constitutes medical advice or guidance for use in humans.
References
Retatrutide has been evaluated in randomised, placebo-controlled human trials through phase 3.
- Triple-Hormone-Receptor Agonist Retatrutide for Obesity - A Phase 2 TrialRandomised, double-blind, placebo-controlled phase 2 obesity trial, 48 weeks.
- Retatrutide, a GIP, GLP-1 and glucagon receptor agonist, for people with type 2 diabetes: a randomised, double-blind, placebo and active-controlled, parallel-group, phase 2 trial conducted in the USARandomised, double-blind, placebo- and active-controlled phase 2 trial; 281 participants with type 2 diabetes.
- Triple hormone receptor agonist retatrutide for metabolic dysfunction-associated steatotic liver disease: a randomized phase 2a trialRandomised phase 2a substudy; 98 participants with metabolic dysfunction-associated steatotic liver disease.
- Efficacy and safety of retatrutide, a GIP, GLP-1, and glucagon receptor agonist, in people with type 2 diabetes and inadequate glycaemic control with diet and exercise (TRANSCEND-T2D-1): a double-blind, randomised, phase 3 trialDouble-blind randomised phase 3 trial in type 2 diabetes (TRANSCEND-T2D-1).
Links open the study record on PubMed so the source can be checked directly. Listing a study is not a claim that its findings apply to any other use, product or route of administration. Research use only.
